You can drop plain script files of type, .ms, .mse or .mcr, either via i-drop controls or directly from file directories. The script is simply evaluated when it is dropped.
Note that DropScripts (MacroScripts implementing 'on dropped do ' handler) can supply an 'on loaded do ...' handler which will be called whenever the dropScript is first loaded during a drag-and-drop operation, either from the web or from a file directory. This allows the dropScript to perform any one-time initialization it might require to set up drop, such as loading ancillary files, etc.